arXiv subjects

Olivia X. M. Yao

Publications and source records attributed to Olivia X. M. Yao.

8 recordsLinked to original sources

arXiv2026

Proofs of some conjectures by Bringmann, Han, Heim, and Kane on periodic sign changes in eta-quotients

Bringmann, Han, Heim, and Kane recently investigated periodic sign patterns in the Fourier coefficients of weakly holomorphic modular forms arising from eta-quotients and posed numerous conjectures in the appendix to their work. Using classical theta-function identities, dissections, and coefficientwise positivity, we prove 72 of these conjectural sign patterns. The eta-quotients considered here have periods 2, 3, 4, 5, 6, 8, and 12. Our proofs are elementary at the level of $q$-series and yield explicit generating functions for the coefficients in each relevant residue class.

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arXiv2026

A proof of the Baruah--Gogoi conjecture on sums of odd and even overlined parts

Andrews and Dastidar introduced the statistic $\SOME(n)$, defined as the difference between the sum of all odd parts and the sum of all even parts occurring in the partitions of $n$, and investigated its arithmetic properties. Motivated by their work, Baruah and Gogoi defined two analogous statistics for overpartitions, namely $\OSOMEo(n)$ and $\OSOMEe(n)$, which record the sums of all odd and all even overlined parts, respectively. They established several congruences for these statistics and their difference, and proposed a conjecture on congruences modulo $7$. In this paper, we prove their conjecture by elementary $q$-series methods. Our proof combines two specializations of Watson's quintuple product identity, a $(p,k)$-parameterization of divisor-sum series, and termwise logarithmic differentiation

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arXiv2026

Proof of a conjecture of Banerjee,Bringmann and Bachraoui on infinite families of congruences

Recently, Andrews and Bachraoui investigated congruences for certain restricted two-color partitions. They made two conjectures for Ramanujan type congruences and a vanishing identity for the limiting sequence. Very recently, Banerjee, Bringmann and Bachraoui confirmed these three conjectures by relating the corresponding generating function to modular forms and mock theta functions. At the end of their paper, they posed a conjecture on infinite families of congruences modulo 4 and 8 for the limiting sequence. The Banerjee-Bringmann-Bachraoui's conjecture implies the two conjectures given by Andrews and Bachraoui. In this note, we settle Banerjee-Bringmann-Bachraoui's conjecture on infinite famlies of congruences based on Banerjee-Bringmann-Bachraoui's results and an identity due to Waston.

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arXiv2026

Some identities on the second order mock theta functions

Recently, Nath and Das investigated congruence properties for the second order mock theta function $B(q)$. In their paper, they asked for analytic proofs of three identities on the second order mock theta functions $A(q)$, $B(q)$ and $μ_2(q)$. In this paper, we settle Nath and Das' open problem by using the $(p, k)$-parametrization of theta functions and several identities due to Hickerson and Mortenson.

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arXiv2025

Parity results for the reciprocals of false theta functions

Recently, Keith investigated arithmetic properties for the reciprocals of some false theta functions and posed several conjectures. In this paper, we prove some parity results for the reciprocals of some false theta functions by using some identities on Ramanujan's general theta function. In particular, our results imply some conjectures of Keith.

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arXiv2025

Proof of a conjecture of Keith on congruences of the reciprocal of a false theta function

Recently, Keith investigated reciprocals of false theta functions and proved some interesting results such as congruences, asymptotic bounds, and combinatorial identities. At the end of his paper, Keith posed a conjecture on congruences modulo 4 and 8 for the coefficients of the reciprocal of a false theta function. In this paper, we not only confirm Keith's conjecture, but also prove a generalized result.

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arXiv2025

Proofs of two conjectures on congruences of overcubic partition triples

Let $\overline{bt}(n)$ denote the number of overcubic partition triples of $n$. Nayaka, Dharmendra and Kumar proved some congruences modulo 8, 16 and 32 for $\overline{bt}(n)$. Recently, Saikia and Sarma established some congruences modulo 64 for $\overline{bt}(n)$ by using both elementary techniques and the theory of modular forms. In their paper, they also posed two conjectures on infinite families of congruences modulo 64 and 128 for $\overline{bt}(n)$. In this paper, we confirm the two conjectures.

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arXiv2025

Congruences modulo arbitrary powers of $5$ and $7$ for Andrews and Paule's partition diamonds with $(n+1)$ copies of $n$

Recently, Andrews and Paule introduced a partition function $PDN1(N)$ which denotes the number of partition diamonds with $(n+1)$ copies of $n$ where summing the parts at the links gives $N$. They also presented the generating function for $PDN1(n)$ and proved several congruences modulo 5,7,25,49 for $PDN1(n)$. At the end of their paper, Andrews and Paule asked for determining infinite families of congruences similar to Ramanujan's classical $ p(5^kn +d_k) \equiv 0 \pmod {5^k}$, where $24d_k\equiv 1 \pmod {5^k}$ and $k\geq 1$. In this paper, we give an answer of Andrews and Paule's open problem by proving three congruences modulo arbitrary powers of $5$ for $PDN1(n)$. In addition, we prove two congruences modulo arbitrary powers of $7$ for $PDN1(n)$, which are analogous to Watson's congruences for $p(n)$.

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